Shunt calibration (NI 9235) when specimen not at rest.

[WyoEng]

I need to perform a shunt calibration for strain gages with 50 feet of extra lead wire.  I learned from Tim Crowe at NI how to do this programmatically in LabVIEW with the NI 9235 hardware, but now I realized there's another aspect of the problem that needs to be addressed.  You see, the gages will be attached to different locations on a wind tower before we have a chance to calibrate them in the program.  And, unless there is no wind at the time (highly unlikely, considering Wyoming is very windy) every time we run the program and perform shunt calibration at the start of the program, there will be some initial strain being applied to the gages.  Will we still be able to perform shunt calibration without messing up the data, or is there a way to perform shunt calibration just once with the lead wires before attaching the gages on site, and saving that data so it can be read into the program?

I'd really appreciate any help or suggestions you can provide.

Thanks,

Bridget

[J-Barticus]

Hi Bridget,

I sent you an email on how we can go about doing a single shunt calibration for your setup, feel free to reply to it with any clarifying questions you may have.

For anyone else interested, you can create a MAX/DAQmx Task in Measurement & Automation Explorer and perform the shunt calibration in the task. The calibration coefficients are saved to that task, so if you use that specific task in LabVIEW it will use the shunt calibration done previously in the task.

-Jake B.